Random Mutational Analysis Targeting Residue K¹⁵⁵ within the Transmembrane β-Hairpin of the Mosquitocidal Mpp46Ab Toxin.

ABSTRACT: Mpp46Ab is a mosquito-larvicidal pore-forming toxin derived from Bacillus thuringiensis TK-E6. Pore formation is believed to be a central mode of Mpp46Ab action, and the cation selectivity of the channel pores, in particular, is closely related to its mosquito-larvicidal activity. In the present study, we constructed a mutant library in which residue K¹⁵⁵ within the transmembrane β-hairpin was randomly replaced with other amino acid residues. Upon mutagenesis and following primary screening using Culex pipiens mosquito larvae, we obtained 15 mutants in addition to the wild-type toxin. Bioassays using purified proteins revealed that two mutants, K155E and K155I, exhibited toxicity significantly higher than that of the wild-type toxin. Although increased cation selec

SUBMITTER: Miyazaki M 

PROVIDER: S-EPMC10741074 | biostudies-literature | 2023 Dec

REPOSITORIES: biostudies-literature